Method for production of a whey protein hydrolyzate

ABSTRACT

A well tasting and organoleptically acceptable whey protein hydrolyzate is produced in high yield by a method using a combination of non-pH-stat hydrolysis and ultrafiltration. Preferably, the method is carried out by mixing a material containing at least 65% whey protein as dry matter and water to form a slurry containing a whey protein content of about 7-20%, heating the slurry to above 600° C., adjusting the pH of the slurry to about 8, hydrolyzing the slurry with at least two different proteases to a degree of hydrolysis of between 17 and 35% without adjusting the pH during hydrolysis to produce a hydrolyzed slurry, inactivating the proteases and separating the hydrolyzed slurry with an ultrafiltration unit having a cut-off value above 10,000 to form a permeate containing the whey protein hydrolyzate. One protease may be obtained from B. Licheniformis and the other from B. Subtilis. The hydrolyzed slurry or the permeate may be treated with activated carbon, and the permeate may be concentrated by nanofiltration and/or by evaporation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of PCT/DK92/00170 filed May 27, 1992, which isincorporated herein by reference.

The invention comprises a method for production of a whey proteinhydrolyzate.

Many methods for production of a protein hydrolyzate with goodorganoleptic properties can be carried out with a low yield only. Thus,it is the purpose of the invention to indicate a method for productionof a protein hydrolyzate with good organoleptic properties, which can becarried out with a relatively high yield.

Surprisingly, according to the invention it has been found that acertain combination of a non-pH-stat hydrolysis and anultrafiltration/microfiltration provides a process for production of awell tasting and organoleptically acceptable product in high yield.

Thus, the method according to the invention for production of a wheyprotein hydrolyzate is characterized by the fact

1) that a whey protein product with at least 65% protein calculated asdry matter and water is mixed to a slurry with a protein content up toabout 20%, preferably up to 12%,

2) that a heat treatment to a temperature above 60° C. is carried out,

3) that the mixture from step 2) is proteolytically hydrolyzed by meansof a protease producible by means of B. licheniformis, preferablyAlcalase®, and/or a protease producible by means of B. subtilis,preferably Neutrase®, by means of a non-pH-stat method to a DH ofbetween 15 and 35%,

4) that the mixture from step 3) is separated on anultrafiltration/microfiltration unit with cut-off value above 10,000,the permeate constituting the protein hydrolyzate, and

5) that the hydrolysis is terminated by inactivation of the enzyme(s).

It is to be understood that all kinds of whey protein products can beused in step 1, e.g. the usual whey protein produced in relation tocheese manufacture.

In regard to the proteolytic enzyme(s) it is especially preferred to useAlcalase® (with a high pH optimum) first, and then Neutrase® (with alower pH optimum). This is especially well suited to thenon-pH-stat-method used according to the invention.

It is to be understood that the enzyme inactivation (step 5)) can becarried out before the ultrafiltration/microfiltration (step 4)). Also,it is to be understood that step 5 can be omitted altogether, if thecut-off value of the membrane is low enough to retain all enzymes in theconcentrate.

A whey protein hydrolyzate with a composition similar to the wheyprotein hydrolyzate produced by means of the method according to theinvention is described in U.S. Pat. No. 4,427,658.

Also, EP 226221 describes a whey protein hydrolyzate, which however, incontradistinction to the whey protein hydrolyzate produced by means ofthe method according to the invention is free from lactose and isproduced by means of the pH-stat techniques.

Also, U.S. Pat. No. 4,293,571, EP 321603 and EP 322589 describe a wheyprotein hydrolyzate, which is produced by hydrolysis with subsequentheat treatment, in contradistinction to the whey protein hydrolyzateproduced by means of the method according to the invention, i.e. bymeans of heat treatment with subsequent hydrolysis. The high values ofthe degree of hydrolysis which can be obtained according to theinvention, cannot be obtained with the prior art methods.

EP 65663 describes a whey protein hydrolyzate, which is produced withoutheat treatment before the hydrolysis, in contradistinction to the methodaccording to the invention.

In Research Disclosure, August 1981 no. 20826 a method similar to themethod according to the invention is described. However, the prior artmethod is restricted to blood as the starting material, and also, theprior art method is performed by means of the pH-stat method.

To the best of the applicant's knowledge, all prior art methods forproduction of a whey protein hydrolyzate give rise to a whey proteinhydrolyzate with an unacceptable taste. The whey protein hydrolyzateaccording to the invention has a marked agreeable taste. Also, inrelation to many of the prior art methods for production of whey proteinhydrolyzate the end product is obtained in a low yield and/or at highproduction cost.

Many of the prior art methods for production of whey protein hydrolyzategive rise to a whey protein hydrolyzate which is not heat stable and notfully soluble in a broad pH interval. The whey protein hydrolyzateproduced by means of the method according to the invention is heatstable and fully soluble in a broad pH interval.

A preferred embodiment of the method according to the inventioncomprises that the slurry in step 1 ) has a protein content of 7-12%. Inthis manner the equipment is utilized optimally, and also, the viscosityis not too high for handling.

A preferred embodiment of the method according to the inventioncomprises that the heat treatment in step 2) is carried out between 70°and 90° C. This temperature interval is especially well suited inrelation to performance of the usually used heat exchangers.

A preferred embodiment of the method according to the inventioncomprises that the pH adjustment in step 3) is carried out by means ofCa(OH)₂ and/or KOH. In this manner a better taste is obtained, and also,a favorable mineral distribution in the final product is obtained. Also,sodium carbonate or sodium phosphate can be used for pH adjustment inorder to precipitate the Ca⁺⁺ in the raw whey protein product.

A preferred embodiment of the method according to the inventioncomprises that the hydrolysis in step 3) is carried out to a DH ofbetween 20-30. In this manner a product with excellent organolepticproperties is obtained.

A preferred embodiment of the method according to the inventioncomprises that the cut-off value of the ultrafiltration/microfiltrationunit is above 50.000. In this manner a very high flux is obtainable.

A preferred embodiment of the method according to the inventioncomprises that the inactivation of the enzyme(s) (step 5)) is carriedout by heat treatment. This inactivation is especially well suited incase the pH of the final protein hydrolyzate is supposed to berelatively high (around neutrality).

A preferred embodiment of the method according to the inventioncomprises that the inactivation of the enzyme(s) (step 5)) is carriedout by acid treatment. This inactivation is especially well suited incase the pH of the final protein hydrolyzate is supposed to berelatively low (acidic).

A preferred embodiment of the method according to the inventioncomprises that the mixture at the end of step 4) is treated withactivated carbon for more than 5 minutes at a temperature, which ispreferably between 50° and 70° C. in an amount corresponding to between1 and 5% carbon, calculated in relation to dry matter content, and thatthe activated carbon is removed. In this manner the flavor is improved.

A preferred embodiment of the method according to the inventioncomprises that after step 5) a concentration is carried out bynanofiltration/hyperfiltration/reverse osmosis at a temperature, whichis preferably between 50° and 70° C. and/or evaporation, whereafter theretentate is collected as the protein hydrolyzate solution. By means ofthe nanofiltration a desalination can be carried out by proper selectionof the membrane; besides nanofiltration/hyperfiltration/reverse osmosisis an inexpensive way for removal of water. Evaporation has theadvantage of obtaining a high dry matter content in the concentratebefore drying.

A preferred embodiment of the method according to the inventioncomprises that the protein hydrolyzate solution from step 5) isspray-dried to a water content below 6.5%. In this manner a stableproduct is obtained, both microbially and organoleptically.

The method according to the invention will be illustrated in thefollowing examples.

For the sake of a better overview a survey of some of the parameterswhich are changed in the examples appear from the table shown below.

    ______________________________________                                               Inacti-          pH                                                           vation           pH      adjustment                                                                             Carbon                               Example                                                                              H = heat UF      N = neutral                                                                           Ca = Ca(OH).sub.2                                                                      treat-                               no.    A = acid modul   A = acid                                                                              Na = NaOH                                                                              ment                                 ______________________________________                                        1      H        PCI     N       Ca       +                                    2      H        PCI     N       Na       +                                    3      A        PCI     A       Ca       +                                    4      H        DDS     N       Ca       +                                    5      H        PCI     N       Ca       +                                    6      H        PCI     N       Ca       +                                    7      H        PCI     N       Ca       +                                    8      A        DDS     A       Na       +                                    ______________________________________                                    

EXAMPLE 1 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2% (E/S is the ratio between ofthe weight of the enzyme and the weight of the protein part of thesubstrate (protein dry matter)).

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the nanofiltration retentate at 55°-60° C.Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             95%                                             ition: Protein in dry matter (N*6.38)                                                                       89.5%                                                  Ash in dry matter      4.4%                                                   Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         5.9                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   24.8%                                           distribu-                                                                            Mw                     1030                                            tion:  Mn                     500                                                    Average peptide chain length                                                                         4.0                                             ______________________________________                                    

EXAMPLE 2 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with 4N NaOH.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1 %. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the nanofiltration retentate at 55°-60° C.Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 3 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

pH-adjustment

pH is adjusted to 4.2 by means of 30% HCl in order to obtain an endproduct suitable for fortifying acidic beverages with protein.

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Pasteurization

The permeate is heat treated for 30 seconds at 75° C. forbacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged.

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the nanofiltration retentate at 55°-60° C.Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 4 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Ultrafiltration Separation

The UF-plant used comprises DDS modules mounted with GR40PP membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged

Treatment with Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as ° Brix is added to the nanofiltration retentate at 55°-60°C. Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter.

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 5 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: Slight off-flavor and a low degree                                            of bitterness                                                          Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 6 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%, Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the mixture at 55°-60° C. Ultrafiltrationis carried out with activated carbon in the retentate.

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate containing the activated carbon is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 7 Feed

The starting material is liquid concentrated whey protein with approx.80% protein calculated as dry matter, produced by ultrafiltration anddiafiltration of whey until the wanted protein content, calculated asdry matter

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with Ca(OH)₂. About 1% of Ca(OH)₂ based on amountof protein is needed.

Hydrolysis

Temperature 53°-54° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.2%

Enzyme 2: Neutrase® 0.5 L. Dosage E/S=1.1%. Neutrase is added when thepH has decreased to <7.0.

Process time 12 hours. The enzymatic hydrolysis is monitored by theosmolality. The increase in osmolality should be 175 mOsm/kg (measuredwith a concentration of 8% of protein in the slurry).

Ultrafiltration Separation

The UF-plant used comprises PCI modules mounted with FP100 membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Inactivation

The permeate is heat treated for 3 minutes at 85° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged.

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the nanofiltration retentate at 55°-60° C.Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         6.5                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   27%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     400                                                    Average peptide chain length                                                                         3.5                                             ______________________________________                                    

EXAMPLE 8 Feed

The starting material is spray-dried whey protein concentrate withapprox. 80% protein calculated as dry matter.

Mixing

The raw material is diluted with deionized water to a protein content of8%. The optimum temperature for fast solubilisation of the protein is55°-60° C.

Heat Treatment

Pasteurisation is carried out in a heat exchanger for at least 2 minutesat 85° C. The purpose is to denature the protein in order to make thehydrolysis more efficient. Also in this manner a very low bacterialcount before the incubation with the enzymes is obtained.

pH Adjustment

pH is adjusted to 8.0 with 4N NaOH.

Hydrolysis

Temperature 55° C.

Enzyme 1: Alcalase® 2.4 L. Dosage E/S=2.0%

Enzyme 2: Trypsin PTN 3.3G. Dosage E/S=3.0%. Trypsin is added when theDH has reached 16% (after 3 hours and 30 minutes).

Total hydrolysis time: 5 hours and 15 minutes. The enzymatic hydrolysisis monitored by the osmolality.

pH-adjustment

The pH value is adjusted to 4.2 by means of 30% HCl in order to obtainan end product suitable for fortifying acidic beverages with protein.

Ultrafiltration Separation

The UF-plant used comprises DDS modules mounted with GR40PP membraneswith cut-off value 100,000.

Concentration to half of the initial volume and subsequent diafiltrationwith twice the volume of the concentrate. Final concentration to maximumdry matter content.

Temperature 60°-65° C.

The retentate which is the main by-product of the process is discharged.

Pasteurization

The permeate is heat treated for 30 seconds at 75° C. in order toinactivate the enzymes and for bacteriological reasons.

Nanofiltration

Concentration to 25°-30° Brix

Temperature 55°-60° C.

The nanofiltration permeate appearing as a by-product is discharged.

Treatment With Activated Carbon

4% activated carbon (Picatif FGV 120) based on amount of dry mattermeasured as °Brix is added to the nanofiltration retentate at 55°-60° C.Reaction time 30 minutes.

Filtration

Removal of activated carbon on plate filter.

Final Products

The whey protein hydrolyzate concentrate with a dry matter content of25% is further processed by sterile filtration and spray-drying, thespray-drying being performed by drying the whey protein hydrolyzateconcentrate at T_(i) =200° C. and T_(o) =75° C. in a spray-dryer withatomization wheel.

Characterization of the Whey Protein Hydrolyzate Concentrate Obtained

    ______________________________________                                        Taste: No off-flavor and a low degree of bitterness                           Compos-                                                                              Dry matter             94.5%                                           ition: Protein in dry matter (N*6.38)                                                                       84%                                                    Ash in dry matter      4%                                                     Fat in dry matter      <0.1%                                           Properties:                                                                          Solubility             Fully soluble                                          pH in solution         4.2                                                    with 5% protein                                                               Osmolality in solution <200 mOsm/kg                                           with 5% protein                                                        Molecular                                                                            Degree of hydrolysis   21%                                             distribu-                                                                            Mw                     800                                             tion:  Mn                     595                                                    Average peptide chain length                                                                         4.8                                             ______________________________________                                    

What is claimed is:
 1. A method for production of a whey proteinhydrolyzate, comprising(a) mixing a material containing at least 65%whey protein calculated as dry matter and water to form a slurrycontaining a whey protein content of about 7-20%; (b) heating the slurryto a temperature above 60° C.; (c) adjusting the pH of the slurry toabout 8; (d) hydrolyzing the slurry by means of at least two differentproteases, to a degree of hydrolysis of between 15 and 35% wherein thepH is not adjusted during the hydrolysis; (e) inactivating saidproteases; and (f) separating the hydrolyzed slurry on anultrafiltration unit with a cut-off value above 10,000, to form apermeate comprising the whey protein hydrolyzate.
 2. The methodaccording to claim 1, wherein one of the proteases is derived from B.licheniformis and the other protease is derived from B. subtilis.
 3. Themethod according to claim 1, wherein the slurry has a protein content of7-12%.
 4. The method according to claim 1, wherein the slurry prior tohydrolysis is pasteurized at a temperature between 70° and 90° C.
 5. Themethod according to claim 1, wherein the pH of the slurry is adjustedusing Ca(OH)₂ and/or KOH.
 6. The method according to claim 1, whereinthe slurry is hydrolyzed to a degree of hydrolysis of between 20-30%. 7.The method according to claim 1, wherein the cut-off value of theultrafiltration unit is above 50,000.
 8. The method according to claim1, wherein the proteases are inactivated by heat treatment afterhydrolysis.
 9. The method according to claim 1, wherein the proteasesare inactivated by acid treatment after hydrolysis.
 10. The methodaccording to claim 1, further comprising, after hydrolyzing the slurryand prior to separating the hydrolyzed slurry, treating the hydrolyzedslurry with activated carbon for more than 5 minutes at a temperature ofbetween 50° and 70° C., wherein the activated carbon is present in anamount of between 1 and 5% carbon, calculated in relation to dry mattercontent, and removing the activated carbon.
 11. The method according toclaim 1, further comprising, after inactivating the proteases, treatingthe permeate with activated carbon for more than 5 minutes at atemperature of between 50° and 70° C., wherein the activated carbon ispresent in an amount of between 1 and 5% carbon, calculated in relationto dry matter content, and removing the activated carbon.
 12. The methodaccording to claim 1, further comprising, after inactivating theproteases, concentrating the permeate by nanofiltration at a temperaturebetween 50° and 70° C. to form a retentate comprising the proteinhydrolyzate, and/or concentrating the permeate by evaporation.
 13. Themethod according to claim 1, further comprising spray-drying thepermeate to a water content below 6.5%.